665215 has 8 divisors (see below), whose sum is σ = 803088. Its totient is φ = 528960.

The previous prime is 665213. The next prime is 665221. The reversal of 665215 is 512566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 665215 - 2¹ = 665213 is a prime.

It is a Duffinian number.

It is a plaindrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 665215.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 880 + ... + 1450.

It is an arithmetic number, because the mean of its divisors is an integer number (100386).

2⁶⁶⁵²¹⁵ is an apocalyptic number.

665215 is a deficient number, since it is larger than the sum of its proper divisors (137873).

665215 is a wasteful number, since it uses less digits than its factorization.

665215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 809.

The product of its digits is 1800, while the sum is 25.

The square root of 665215 is about 815.6071358197. The cubic root of 665215 is about 87.2945930126.

The spelling of 665215 in words is "six hundred sixty-five thousand, two hundred fifteen".